Improved method of treating leather scraps



UNITED STATES PATENT FFICE.

HENRY B. FARWELL, OF BOSTON, MASSACHUSETTS.

Specification forming part of Letters Patent N0. 53,800, dated April 10,1866.

To all whom "it may concern:

Be it known that I, HENRY B. FARWELL, of Boston, in the county ofSuffolk and State of Massachusetts, have made a new and useful inventionhaving reference to the Treatment of Whitenings, or NVaste Portions orScraps of Leather, in order to extract and purify the oleaginous matterswith which they have been impregnated; and I do hereby declare the sameto be fully set forth in the foL lowing description.

It is a fact well known to those conversant with the tanning andcarrying of hides and skins that a great amount of valuable fattymatters is yearly lost in the whitening and scraps of leather, which areusually either burned or thrown away. To recover the tallow oroleaginous matters from such is the main object of my invention.

In carrying out my invention I provide a vat or vessel of any desirablecapacity and furnish the same with a cover. Into this vessel I put aslarge a quantity as may be desirable of the scraps or waste portions ofleather to be acted on. Next I put into the said vessel a sufficientquantity of water to cover the said portions. Next, by means of steamintroduced into the vessel, I raise the water thereof to a boilingtemperature and main-. tain the same in a state of ebullition for abouttwo hours, or until the fat or oil may have been expelled from theleather. I would remark that a large kettle or metallic boiler might beemployed and the water heated by the application of fire underneath suchvessel or boiler; but this latter mode I do not consider so good in manyrespects as the former.

The tallow or fatty matters, owing to their lighter specific gravity,will rise to the surface of the water, and may be. either skimmedtherefrom into another vessel or may be suffered to remain until theymay have become cooled, when the concrete mass may be removed.

In order to free the tallow from any foreign matter with which it may beimpregnated, I put into the mass, when it has been sufficiently boiled,a small quantity of the oil of vitriolthat is to say, one pound of thevitriol to three hundred gallons of water. This I have found has theeffect of freeing in a great measure the tallow from the impurities withwhich it was combined.

By my improvement I am enabled to recover and utilize a large percentageof valuable fatty matter which has heretofore been usually wasted.

I claim 1. Recovering the tallow or fatty matters from whitenings orscraps of leather in the manner as set forth.

2. In combination with the same, the employment of oil of vitriol, asand for the purpose set forth.

HENRY B. FARWELL.

Witnesses OLIVER W001), SAML. J oNEs.

